Rock drilling rig and method of driving compressor

ABSTRACT

A rock drilling rig and a method of driving a compressor, wherein the rock drilling rig is operated by a combustion engine and is provided with a flushing system including a compressor for producing pressurized air. The compressor is driven by an electric drive motor. The combustion engine is connected to drive a generator, which produces electric energy that is stored in an energy storage. The stored electric energy can be utilized in driving the compressor.

BACKGROUND OF THE INVENTION

The invention relates to a rock drilling rig, and particularly to anarrangement for driving a compressor of the rock drilling rig.

The invention further relates to a method of driving a compressor of arock drilling rig.

The field of the invention is defined more specifically in the preamblesof the independent claims.

In mines and other work sites rock drilling rigs are used for drillingbore holes to rock surfaces. Typically the rock drilling rig comprisesan internal combustion engine for producing needed energy. Further, therock drilling rig is provided with a boom and a drilling unit in theboom. During a drilling procedure drilling cuttings are formed in thebore hole. The drilling cuttings are flushed away from the bore hole bymeans of flushing medium. Typically pressurized air is used forflushing. Thus, the rock drilling rig includes a compressor forproducing the needed flushing air. It has been noted that a flushingsystem causes significant loading to the combustion engine.

BRIEF DESCRIPTION OF THE INVENTION

An object of the invention is to provide a novel and improved rockdrilling rig provided with a compressor arrangement and a method ofdriving a compressor.

The rock drilling rig according to the invention is characterized inthat the at least one compressor of the flushing system is driven bymeans of at least one electric compressor drive motor connected to theelectric system.

The method according to the invention is characterized by driving thecompressor by means of an electric compressor drive motor mechanicallyindependently of the combustion engine.

An idea of the disclosed solution is that a combustion-engine-operatedrock drilling rig is provided with a compressed air system comprisingone or more compressors. The compressor is driven by one or moreelectric motors. Kinetic energy produced in the combustion engine is nottransmitted to the compressor.

An advantage of the disclosed solution is that the compressor can bedriven mechanically and physically independently of the combustionengine of the rock drilling rig. The compressor can be driven accuratelyand according to the need for pressurized air. This way, unnecessaryproduction of compressed air can be avoided and fuel consumption of acombustion engine can be decreased.

According to an embodiment, electric energy is charged in one or moreelectric energy storages and the stored electric energy is utilized indriving the electric motor of the compressor. Thanks to the use ofstored electrical energy, loading and fuel consumption of a combustionengine can be decreased. The energy storage makes it possible to balancethe loading of the combustion engine, whereby a combustion engine withlower power capacity can be used.

According to an embodiment, the electric compressor drive motor isdriven only by means of electric energy received from the energystorage.

According to an embodiment, the electric compressor drive motor isdriven by means of electric energy received from the energy storage andthe generator driven by the combustion engine. The use of the energystorage decreases loadings of the generator and the combustion engine.

According to an embodiment, output capacity of the combustion engine isdimensioned by taking into account the lower power need due to theelectric drive of the compressor and electric power taken from theelectric storage. The combustion engine may then be dimensioned to havelower power capacity, whereby the engine may be smaller in size and lessexpensive.

According to an embodiment, the electric energy storage is a battery ora battery package including several batteries.

According to an embodiment, the combustion engine is a diesel engine.

According to an embodiment, the rock drilling rig comprises a controlunit for controlling the operation of a flushing system. The controlunit monitors the drilling unit and detects the need for pressurizedair. Based on the monitoring, the control unit is configured toautomatically adjust the running speed of the compressor. This way, theproduction of pressurized air, i.e. pressure and flow, is adjustedaccording to the drilling process and consumption of pressurized air.

According to an embodiment, the rock drilling rig comprises a controlunit for controlling the operation of the flushing system. The controlunit monitors a tramming unit and detects if a carrier istransfer-driven. Based on the monitoring, the control unit is configuredto automatically switch off the electrical compressor drive motor forduration of the detected transfer drive. In this way, unnecessaryproduction of pressurized air during the transfer drive is avoided.

According to an embodiment, the operator switches off the electriccompressor drive motor for the duration of a transfer drive of the rockdrilling rig. Further, the compressor can be stopped for the duration ofany other interruptions in the drilling procedure and situations whenthere is no need for pressurized air. In this way, unnecessaryproduction of pressurized air is avoided and energy is saved.

According to an embodiment, the electric system comprises at least onecontrol device for controlling rotation of the electric compressor drivemotor. The drive of the compressor drive motor can be controlledsteplessly. The control device for controlling running of the electricmotor can be a frequency converter, such as an inverter or a DC/ACconverter. Thanks to this embodiment, the output capacity of thecompressor can be adjusted in a versatile and effective way, andfurther, the control is accurate too. Alternatively, the drive of thecompressor drive motor can be controlled in predetermined steps orramps.

According to an embodiment, the tramming unit comprises one or moreelectric tramming drive motors connected to the electric system andgenerating power for the transport drive. Electric energy stored in oneor more electric energy storage can be utilized in either entirely orpartly when running the tramming motor. Thanks to the use of storedelectrical energy, loading and fuel consumption of a combustion enginecan be decreased.

According to an embodiment, the rock drilling machine is electricallyoperated and connected to the electrical system. Electrical energystored in one or more electrical energy storage can be utilized eitherentirely or partly when running the rock drilling machine. Thanks to theuse of stored electrical energy, loading and fuel consumption of acombustion engine can be decreased.

According to an embodiment, the rock drilling rig comprises at least oneauxiliary unit which is electrically operated. The auxiliary unit may bea hydraulic unit, for example. The hydraulic unit may produce neededhydraulic pressure for hydraulic cylinders of a boom and other hydraulicauxiliary actuators. The hydraulic unit comprises a hydraulic pump whichis electrically driven and connected to the electric system. Electricenergy stored in one or more electric energy storages can be utilizedeither entirely or partly when running the hydraulic pump. Thanks to theuse of stored electric energy, loading and fuel consumption of acombustion engine can be decreased.

According to an embodiment, the rock drilling rig comprises a controlunit which is configured to determine the drilling efficiency during adrilling process. The control unit may control an electric system toincrease storage of electric energy to an energy storage when drillingis performed under maximum efficiency. Thus, when a drilling unit needsless power and the combustion engine has free capacity, more electricenergy can be generated by a generator and then stored in the energystorage. Possible extra capacity can be used for charging batteries.

According to an embodiment, the rock drilling rig comprises a controlunit which is configured to determine current loading of a combustionengine. The control unit may control an electric system to increaseconsumption of electric energy stored in an energy storageproportionally to the detected increase in load of the combustionengine. In this way, electric energy of the batteries are used more andmore for driving different electric drive motors connected to theelectric system in situations when the combustion engine is heavilyloaded. This embodiment balances the loading of the combustion engine.

According to an embodiment, the disclosed solution is utilized in tophammer drilling. The drilling unit comprises a top hammer typepercussion device which is located at the opposite end of a drillingtool relative to the drill bit.

According to an embodiment, the disclosed solution is utilized indown-the-hole (DTH) drilling. The drilling unit comprises a down-thehole type percussion device which is located at the same end of thedrilling tool as the drill bit.

According to an embodiment, the disclosed solution is utilized in rotarydrilling. The drilling unit is without any percussion device but,instead, a drilling tool is rotated by means of a rotating device.

According to an embodiment, the disclosed compressor arrangement andprocedure are intended for a surface drilling rig which is designed forabove ground drilling in opencast mines and other working sites, such asin road, construction and other contracting work sites.

According to an embodiment, the disclosed control procedures are carriedout by executing one or more software or computer programs designed forthe purpose. The computer program comprises program code meansconfigured to execute the disclosed actions and steps when run on acomputer.

Above disclosed embodiments can be combined in order to form suitablesolutions provided with necessary features.

BRIEF DESCRIPTION OF THE FIGURES

Some embodiments are described in more detail in the accompanyingdrawings, in which

FIG. 1 is a schematic side view showing a rock drilling rig for surfaceworking sites,

FIG. 2 is a schematic view showing a principle of down-the-holedrilling,

FIG. 3 is a schematic side view showing a rock drilling rig forunderground working sites,

FIG. 4 illustrates a control block diagram of a control system of a rockdrilling rig, and

FIG. 5 is a simplified chart showing an electric system of a rockdrilling rig.

For the sake of clarity, the figures show some embodiments of thedisclosed solution in a simplified manner. In the figures, likereference numerals identify like elements.

DETAILED DESCRIPTION OF SOME EMBODIMENTS

FIG. 1 shows a feasible rock drilling rig 1 comprising a movable carrier2 which is provided with one or more booms 3 equipped with a drillingunit DR. The drilling unit DR may comprise a feed beam 5 provided with arock drilling machine 7 that can be moved on the feed beam 5 by means ofa feed device 6. The rock drilling machine 7 may comprise a percussiondevice for generating impact pulses on a tool 8, and a rotating devicefor rotating the tool 8. Further, the rig 1 may include a flushingsystem FS comprising one or more compressors CO for producing compressedair which may be conveyed through a flushing channel 9 to the drillingmachine 7 and through the tool 8 to a bore hole 10.

Further, the rock drilling rig 1 may comprise a hydraulic system, whichincludes a hydraulic pump HP, hydraulic channels, a tank and necessarycontrol means, such as valves and the like. Further, one or morehydraulic actuators may be connected to the hydraulic system.

The rock drilling rig 1 also comprises one or more control units CUarranged to control the systems of the rock drilling rig 1. The controlunit CU may be a computer or a corresponding control device comprising aprocessor, a programmable logic or any other control device suitable forthe purpose, to which it is possible to set at least one controlstrategy, according to which the control unit carries out controllingindependently or in cooperation with the operator.

At a drilling site, one or more boreholes are drilled with the drillingunit DR. After the drilling operation, the rig 1 is moved to the nextdrilling site or position. The rock drilling rig 1 is provided withdrive equipment which includes transmission 11 for conveying rotationalmovement to moving members 12, such as chain tracks or wheels. On thecarrier 2, there is also a combustion engine DI, which may be a dieselengine. The combustion engine DI serves as a power unit for producingneeded kinetic energy. The kinetic energy can be transmitted via thetransmission 11 to the moving members 12 and further to one or moregenerators for producing needed electrical energy. Electric energy canbe stored in one or more energy storages BAT, such as a battery or abattery package. The compressor CO and the hydraulic pump HP can becontrolled according to the principles described in this patentapplication. Further, the needed kinetic power for transport drive canbe formed by means of one or more electric tramming drive motors whichmay also be controlled as disclosed above.

FIG. 2 illustrates a basic principle of a drilling unit DR fordown-the-hole DTH drilling, which differs from the top-hammer-drillingshown in FIG. 1 in such way that a percussion device 13 is arranged atan opposite end of a tool 8 as compared to a rotating device 14 of thedrilling machine 7. It is also possible that the drilling machine doesnot include any percussion device, whereby it is called rotary drilling.The above-disclosed flushing system and control principles can beapplied to DTH and rotary drilling too.

FIG. 3 discloses a rock drilling rig 1 suitable for underground drillingwhen tunnels and rock cavities are excavated, and also when ore ismined. Principles and embodiments disclosed above apply also to thistype of rock drilling.

FIG. 4 shows a control system 15 comprising one or more control units CUand input means 16 for feeding control data and commands to the controlunit CU. The input means may include a control device 17, such as ajoy-stick, and an input device 18, such as a keypad, by means of whichan operator 19 may communicate with the control unit CU. Further, thecontrol unit CU may read data from one or more memory units 20 and alsostore data therein. The control unit CU may be provided with one or morecontrol strategies 21 including operating principles and guidelines forcontrolling the flushing system FS and possibly also other electricsystems of the rock drilling rig, such as the traction system andauxiliary systems. The control strategy 21 may include an algorithm forautomatically controlling the electric compressor drive motor CM.Control data and parameters may be stored in the memory unit or media20. Monitoring information and measuring data may be gathered by meansof sensors or measuring devices from the systems and actuators connectedto the electric system. Also the operation of the combustion engine DIcan be monitored. Monitoring or sensing data can be transmitted to thecontrol unit CU. The control unit CU may be a computer equipped with anappropriate processor capable of running a software program including acontrol algorithm and also processing measuring data for producingcontrol information. On the basis of the measuring data, manual controlcommands and the control strategy, the control unit CU produces controlcommands for the disclosed system and allows the disclosed controlaccording to the above presented principles.

In FIG. 5 it is shown a simplified chart of an electric system ES of arock drilling rig. The combustion engine DI drives the generator GEN andelectric energy is produced. By means of the generated electric energy,the electric system of the drilling rig is driven. The drilling unit DR,the tramming unit TR and the auxiliary unit, such as the hydraulicsystem HS, can be driven by the energy produced by the generator GEN.Further, the generated energy can be used to charge the energy storageBAT. There may be a voltage transformer between the generator and theenergy storage. The flushing system FS can be driven by means of theenergy stored in the energy storage BAT. Alternatively electric energycan be directed to the flushing system FS from two sources, namely fromthe energy storage BAT and the generator GEN.

The flushing system FS may further include a control device CD, whichmay comprise a frequency converter, by which the rotation of theelectric compressor drive motor CM can be controlled steplessly. Theoperation of the control device CM may be controlled by a control unitCU.

The drawings and the related description are only intended to illustratethe idea of the invention. In its details, the invention may vary withinthe scope of the claims.

1. A rock drilling rig comprising: a movable carrier; a tramming unitfor performing transfer drive of the carrier; at least one drilling boommovable relative to the carrier and provided with a drilling unitincluding a rock drilling machine; a flushing system having at least onecompressor for producing pressurized air utilized in flushing a drillhole during drilling; a combustion engine for producing kinetic energy;at least one generator arranged to be driven by the combustion engineand arranged to produce electric energy to an electric system; and atleast one energy storage connected to the electric system, wherein therock drilling rig is combustion engine operated, needed electric energyof the rock drilling rig is produced by the at least one generator; andthe at least one compressor of the flushing system is driven by means ofat least one electric compressor drive motor connected to the electricsystem.
 2. A rock drilling rig as claimed in claim 1, wherein the atleast one electric compressor drive motor is driven by means of electricenergy received from the at least one energy storage.
 3. A rock drillingrig as claimed in claim 1, wherein the at least one electric compressordrive motor is driven by means of electric energy received from the atleast one energy storage and the at least one generator.
 4. A rockdrilling rig as claimed in claim 1, wherein the rock drilling rigincludes at least one control unit for controlling the operation of theflushing system; the control unit is arranged to monitor the drillingunit; and the control unit is arranged to adjust the running speed ofthe compressor and the production of pressurized air according to thedrilling process.
 5. A rock drilling rig as claimed in claim 1, whereinthe rock drilling rig includes at least one control unit for controllingthe operation of the flushing system; the control unit is arranged tomonitor the tramming unit and to detect transfer drive of the carrier;and the control unit is arranged to switch off the electric compressordrive motor for the duration of the transfer drive.
 6. A rock drillingrig as claimed in claim 1, wherein the electric system includes at leastone control device for controlling rotation of the electric compressordrive motor.
 7. A rock drilling rig as claimed in claim 1, wherein thetramming unit includes at least one electric tramming drive motorconnected to the electric system and generating power for the transportdrive.
 8. A rock drilling rig as claimed in claim 1, wherein the rockdrilling machine is electrically operated and connected to the electricsystem.
 9. A rock drilling rig as claimed in claim 1, wherein the rockdrilling rig includes a hydraulic system and hydraulic actuatorsconnected to the hydraulic system; the hydraulic system (HS) includes atleast one hydraulic pump for generating hydraulic pressure; and thehydraulic pump is electrically driven and connected to the electricsystem.
 10. A method of driving a compressor of a rock drilling rigwhich is provided with a combustion engine, the method comprising thesteps of: driving a compressor by means of a motor; conducting producedpressurized air to a flushing system; producing the needed electricenergy for an electric system of the rock drilling rig by at least onegenerator driven by the combustion engine; and driving the compressor bymeans of an electric compressor drive motor mechanically independentlyof the combustion engine.
 11. A method as claimed in claim 10, whereinthe electric compressor drive motor is driven by utilizing electricenergy stored in at least one energy storage.
 12. A method as claimed inclaim 10, wherein the production of pressurized air is adjustedaccording to the drilling process.
 13. A method as claimed in claim 10,further comprising determining drilling efficiency during a drillingprocess; and increasing storage of electric energy to at least oneenergy storage when drilling is performed under maximum efficiency. 14.A method as claimed in claim 10, further comprising determining currentloading of the combustion engine; and increasing consumption of electricenergy stored in at least one energy storage proportionally to thedetected increase in the load of the combustion engine.
 15. A method asclaimed in claim 10, further comprising determining the current use ofcompressed air; and switching off the electric compressor drive motorwhen com-pressed air is not used.